Trane SCXG-SVX01B-EN manual Time Clock Option, pre-startup, Installation requirements

pre-startup

Installation requirements

Time Clock Option

The time clock option has a programmable timer that is factory wired to the unoccupied input to provide on/off control. The time clock will not allow the unit to pass through the night setback/ morning warmup mode, except on units with optional night heat/morning warm up, or programmable night setback. See Figure I-PR-22.

The timeclock, a “Digi 20” by Grasslin, is

inside the control panel, but accessible

Figure I-PR-22. Grasslin time clock option with the control panel door closed. This same type timer is also used for pro- grammable night setback/morning warm up. Programming instructions for the “Digi 20” timer are in the “Program- ming” section.

Time Clock Installation

1. Ensure operating temperature is between 4°F and 131°F.

2. Locate the time clock at least 5 feet away from any large electrical contact or machinery to avoid possible electrical interference problems.

3. Provide a separate independent circuit for the time clock power supply.

4. Since all electronic instruments are sensitive to voltage spikes, pay close attention tot he following:

a. If possible, supply power to the electronic time clock from a phase different than the one supplying power to the load.

b. Provide a suitableVaristor or RC network across the INDUCTIVE LOADS supply terminals to reduce voltage spikes.

c. Place a diode across the DC OPERATED INDUCTOR terminals to eliminate back EMF.

d. HIGHLY INDUCTIVE LOADS, especially fluorescent lights, may require a relay in which case step a. and c. apply.

The timeclock can be surface or flush mounted. Lift off the front cover and loosen the two screws on opposite corners. Pull off the base’s plug with a left to right rolling motion.

Time Clock Installation Checklist

1.Ensure operating temperature is 4°F to 131°F.

2.Locate the time clock at least 5 feet away from any large electrical contact or machinery to avoid possible electrical interference problems.

3.Provide a separate independent circuit for the time clock

power supply.

4.Since all electronic instruments are sensitive to voltage spikes, pay close attention to the following:

a. If possible, supply power to the electronic time clock from a phase different than the one supplying power to the load

b. Provide a suitableVaristor or RC network across the INDUCTIVE LOADS supply terminals to reduce voltage spikes.

c. Place a diode across the DC OPERATED INDUCTOR terminals to eliminate back EMF.

d. HIGHLY INDUCTIVE LOADS, especially fluorescent lights, may require a relay in which case (A) and (C) apply.

The Digi 20A timeclock unit can be surface or flush mounted. Lift off the front cover and loosen the two screws on opposite corners. Pull off the base’s plug with a left to right rolling motion.

Surface Mounting Inside Panel

Place screws through the base’s preset holes and screw to back of panel or wall.

Wire according to the instructions in the following section. Depending upon the specific installation, you may find it more convenient to complete wiring before attaching the base.

Place the terminal cover over the terminal block by aligning the two screws with the corner holes in the base. Push the timer firmly onto the plug in the base. Tighten the two screws. A base for DIN rail mounting is optional.

Wiring theTimeclock

1.Wire 24, 120, or 220 VAC to input terminals. Make sure to apply correct voltage. Using incorrect voltage will void the warranty.

2.Connect wire to the screw terminals according to the unit wiring diagrams. Use 12 to 22 AWG wire.

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